Liquid level indicator



Sept. 5, 1933. E;l CARETTA 1,925,747

' LIQUID LEVEL INDICATOR Filed June 10, 1929 uuuuuuuuu uwuuuunuygggjau- Patented sept. l5, 1933 UNITED STATES 1,925,747 LIQUID LEVEL lNnloA'roa' Ettore Caretta, Turin, Italy Application June 10, 1929, Serial No. 369,606, and in Italy June 19, 1928 The present invention relates to devices intended to detect the level of a liquid contained in a receiver of the kind comprising a control member mounted to move vertically in said receiver and actuated from the outside, said member being stopped at the time it abuts on a float which follows the level of the liquid.

The present invention has for its object a device of this kind which comprises means for stopping immediately and for easily releasing said movable control member, such results being secured by the fact that thesaid movable control member on reaching the float, locks the latter by exerting on it an action which jams tion the essential parts of an embodiment of the device of this invention;

Figure 3 is a central section of the parts of a device comprising an annular oat guided lon a central rod;

Figure 4 is a sectional view on line 4--4 of Figure 3*;

Figure 5 is a central section of a Adevice iny which the float is mounted within a tube; Figure 6 shows a modified construction; Figure '7 is a sectional detail view to an enlarged scale of the end part of the movable member intended to act on the float.

In the level indicator arrangement shown in Figure l, 1 is the top wall of a receiver in which is secured a vertical guide rod 2. Said guide rod is `encircled by an annular float 3, having a central lining sleeve 8, which isable r to move freely along it. Said guide rod 2 is hollow and has a longitudinal slot 4 and in said hollow rod 2 is free to move a metal wire or cable 5 which extends outside of hollow rod 2 and has its free end connected with a manipulating member 19 adapted to slide along al guide member 20 having a scale 2 1; a sheath 18 encircles said cable 5 and has its ends abutting on top end of hollow rod 2 and guide 20 as conventional in flexible transmissions. The end of cable 5 lying within the hollow guide rod 2 has a head 5' guided to reciprocate within hollow said float on a part guiding it, while the condi-V Figure 2 illustratesl separately in central sec-A rod 2 and provided with a transverse arm 6 extending through slot 4 and carrying an outer downward projection on '7. Arm 6 is thus caused to move along hollow rod 2 while standing substantially perpendicular to the'axis of 60 rod 2 owing to they guide afforded by head 5' within bore of hollow rod 2. A

In operation, when the manipulating member 19 is manipulated to move down the arm 6, the projection 7 of said arm produces an eccen- 65 tric thrust on iloat 3, and said action causes float 3 to swing into the position shown in dotted lines the angle of swinging being exaggerated in the drawing for purpose of illustration; V thus a jammingaction vof the edges of the in- 'p70 ternal sleeve or lining of the float on the surface of the guide rod 2 is produced and iloat 3 is locked on said guide rod 2, arm 6 with cable 5 and manipulating member 19 being prevented from being further moved down by the engagement of projection '7 with float 3 and by the v guide afforded by hollow rod 2 to head 5 which prevents said arm 6 fromrocking with respect to hollow rod 2; the manipulating member 19 is thus stopped along scale 21 in a position giv- 804 ing an indication as to the level of the liquid in the receiverl. 4

The same result may be secured in improved conditions, both as to the constructionof the apparatus and to its operation, by securing the necessary cooperation of the oat and feeling member which is inside the tubular rod 2, by means of a member carried by the iloat and entering the slot of the tubular ro d 2 to receive the action of said operating member. 9

Figure 2 shows an embodiment of a level indicator according to this invention in which the abovestated condition is secured. In this construction the sleeve 8 of float 3 comprises projecting arms 9 in which is journalled a roller 95 10 which is free to extend into hollow guide rod 2 through slot 4fof Ithe same while the member manipulated by operator consists of a plunger 11 which on coming in contact with roller 10, causes it to move outwardly and therefore causes the float3 to rock, it receiving a thrust whose line of action does not pass through the center of buoyancy of said float, and to be jammed by the opposed edges of its sleeve 8 on the guide rod 2. The provision of a roller 10 for cooperation with the plunger 11 has, with respect to the use of a member arranged -in stationary manner on the float, the advantage that the upward or release nlotion of said plunger is assisted by the fact that the engagement between the roller 10 and the plunger 11 is frictionless or rolling in character. l

Figures 3 and 4 show another construction of a. level indicator according to this invention in which the roller l0is located in a recess 22 of float 3 which has a comparatively large extent in a direction parallel with guide rod 2, While said sleeve 8 has its bore enlarged on a portion of its longitudinal extent as shown by 8' to produce a narrower region 8 for engagement with the rod 2 whose top and bottom edges Sci-8b are intended to come into jamming contact with the guide rod 2.

As above referred to, roller 10 makes easy the release of plunger 1l and therefore said'plunger cannot become jammed with the float.

In the construction of Figure 5, the float 3 is mounted within a tube 12 and it comprises a ran dial arm 13 extending into the central Vhollow rod 2 through the slot 4 of the same, said hollow rod 2 operating as a guide for a plunger 11 connected with the wire or cable 5.

Figure 6 shows a construction in which an annular float 3 is mounted on a solid guide rod 15 and carries a radial arm 13 extending into a slotted tube 2 along which the plunger 11 is mounted to move.

In the constructions of Figures 5 and 6 when the plungerll acts on the arm 13, oat 3 receives an eccentric action and therefore it is caused to swing and take up a position in which it is jammed within the tube 12l or on rod 14 respectively and is locked thereon; also in these constructions the action of the plunger 1l on the arm 13 is such as to prevent any possible jamming interaction of said plunger ll and arm 13.

In any case the manipulating member 19 cannot be shifted after the end part 11 of the cable 5 has engaged the oat 3 and it is thusin conditions to show the level -of the liquid on the scale 21.

The end of the, Wire or cable is preferably provided with a hollow plunger 16 shown in detail in Figure 7 which is engaged on enlarged knob 17 provided at the end of the cable or wire 5. For this purpose a plunger 16 is availed of which has cylindrical recess 16 having a depth larger than longitudinal length of knob 17; knob 17 is introduced into said recess land then the edge of the mouth of said recess is crimped over said knob 17 as at 16 to engage it in said recess 16 of plunger 16; said plunger 16 has conveniently a tapering shape in its region intended to engage roller 10 as illustrated.

The feeling member consisting of cable 5 and plunger 16 may be freely inserted and removed in and from tubular guide rod 2 without interference by the float or members carried thereby.

The described device provides for locking the manipulating and indicating member 19 in a* position in register vwith the liquid level by taking advantage of the oat as a clamping member, this result being secured in conditions such as said movable member must -merely produce a thrust and it is never required to heavily engage another member thus removing any possible jamming of said member and reducing to a minimum the pull required to move it up. What I claim as my invention and desire to secure by United States Letters Patent is:

1. An indicator for indicating the level of a liquid in a receiver comprising a tubular rod having a slot therealong, an annular oat encircling said tubular rod and movable along it, a member journalled on said oat and extending into said tubular rod through said slot of *the same, a feeling member mounted to move in said tubular rod for engagement with said journalled member, a manipulating `member for actuating said feeling member and indicating means mov-- ing in unison with said manipulating member.

2. in indicator for indicating the level of a liquid in a receiver comprisinga tubular rod having a slot therealong, an annular oat encircling said tubular rod and movable along it, said oat bearing on said tubular rod by a comparatively short span in the direction of the axis of said tubular rod, a roller journalled on said float at a point at a comparatively large distance from the middle point of said float region and extending into said tubular rod through said slot of the same, a feeling member mounted to move in said tubular rod for engagement with said roller, a manipulating member for actuating said feeling member and indicating means moving in unison with said manipulating member.

3. An indicator for indicating the level of a liquid in a receiver comprising a guide rod, an annular float encircling said guide rod` a sleeve in the central bore of said annular'float, said sleeve having a surface for engagement with said guide rod which is shorter than' the float size in the direction of the axis of said guide rod, a feeling member mounted to move; along said guide rod, a manipulating member for actuating said feeling member, indicating means moving in unison with said manipulating member and frictionless cooperating means on said float and feeling member to tilt said oat and clamp said sleeve and iioat on said guide rod on engagement of said means to stop said feeling member.

4. An indicator for indicating the level of a liquid in a receiver comprising a tubular rod having a slot therealong, an annular float encircling said tubular rod and movable along it. said float embracing said tubular rod by a region which has a comparatively short span in the direction of the axis of said tubular rod, a member journaled on said float at a point at a comparatively large distance from the middle point of said float region and extending into said tubular rod through said slot of the same, a feeling member mounted to move in said tubular rod .comprising a llexible member and a tapering plunger for engagement with said journalled member. a manipulating member for actuating l ETTORE CARETTA. 

